/* ===== MODERN CSS RESET & VARIABLES ===== */

:root {

    /* Color Palette - Enhanced for Better Visibility */

    --primary: #1e40af;

    --primary-dark: #1e3a8a;

    --secondary: #7c2d12;

    --accent: #059669;

    --success: #16a34a;

    --warning: #d97706;

    --error: #dc2626;



    /* Neutral Colors - Higher Contrast */

    --white: #ffffff;

    --gray-50: #f8fafc;

    --gray-100: #f1f5f9;

    --gray-200: #e2e8f0;

    --gray-300: #cbd5e1;

    --gray-400: #94a3b8;

    --gray-500: #64748b;

    --gray-600: #475569;

    --gray-700: #334155;

    --gray-800: #1e293b;

    --gray-900: #0f172a;



    /* Typography */

    /* Prefer system fonts for fastest LCP; if 'Inter' and 'JetBrains Mono' are loaded globally, preconnect above will help. */

    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Helvetica Neue', Arial, sans-serif;

    --font-mono: Consolas, 'Liberation Mono', Menlo, monospace;



    /* Spacing */

    --space-1: 0.25rem;

    --space-2: 0.5rem;

    --space-3: 0.75rem;

    --space-4: 1rem;

    --space-5: 1.25rem;

    --space-6: 1.5rem;

    --space-8: 2rem;

    --space-10: 2.5rem;

    --space-12: 3rem;

    --space-16: 4rem;

    --space-20: 5rem;

    --space-24: 6rem;



    /* Shadows */

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);

    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);

    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);

    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);



    /* Border Radius */

    --radius-sm: 0.125rem;

    --radius: 0.25rem;

    --radius-md: 0.375rem;

    --radius-lg: 0.5rem;

    --radius-xl: 0.75rem;

    --radius-2xl: 1rem;

    --radius-full: 9999px;

}



/* ===== GLOBAL STYLES ===== */

html {
    scroll-behavior: smooth
}

* {

    box-sizing: border-box;

    margin: 0;

    padding: 0;

}



body {

    font-family: var(--font-sans);

    line-height: 1.6;

    color: var(--gray-900);

    background-color: var(--white);

}



/* ===== HERO SECTION ===== */

.hero {

    position: relative;

    min-height: 80vh;
    /* Lower height to improve LCP */

    display: flex;

    align-items: center;

    justify-content: center;

    background: linear-gradient(135deg, #1e40af 0%, #7c2d12 100%);

    overflow: hidden;

    padding: var(--space-8) var(--space-4);

}



.hero::before {

    content: '';

    position: absolute;

    top: 0;

    left: 0;

    right: 0;

    bottom: 0;

    /* Lighter overlay to reduce paint cost */

    background: linear-gradient(to bottom, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0));

    opacity: 0.25;

}



.hero-content {

    position: relative;

    z-index: 2;

    text-align: center;

    max-width: 1200px;

    width: 100%;

    color: var(--white);

}



.hero-title {

    font-size: clamp(2.5rem, 5vw, 4rem);

    font-weight: 800;

    line-height: 1.1;

    margin-bottom: var(--space-6);

    /* Remove hero animation for faster LCP */

    color: #ffffff;

    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);

}



.hero-subtitle {

    font-size: clamp(1.25rem, 2.5vw, 1.75rem);

    font-weight: 600;

    margin-bottom: var(--space-8);

    opacity: 0.95;

    /* Remove hero animation for faster LCP */

    color: #ffffff;

    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);

}



.hero-description {

    max-width: 800px;

    margin: 0 auto var(--space-12);

    font-size: var(--space-5);

    line-height: 1.7;

    opacity: 1;

    animation: fadeInUp 1s ease-out 0.4s both;

    color: #ffffff;

    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);

}



.hero-cta {

    display: flex;

    gap: var(--space-4);

    justify-content: center;

    flex-wrap: wrap;

    animation: fadeInUp 1s ease-out 0.6s both;

}



.btn {

    display: inline-flex;

    align-items: center;

    gap: var(--space-2);

    padding: var(--space-4) var(--space-8);

    border-radius: var(--radius-full);

    font-weight: 600;

    font-size: var(--space-4);

    text-decoration: none;

    transition: all 0.3s ease;

    border: none;

    cursor: pointer;

}



.btn-primary {

    background: var(--white);

    color: var(--primary);

    box-shadow: var(--shadow-lg);

}



.btn-primary:hover {

    transform: translateY(-2px);

    box-shadow: var(--shadow-xl);

    color: var(--primary);

    text-decoration: none;

}



.btn-secondary {

    background: rgba(255, 255, 255, 0.1);

    color: var(--white);

    border: 2px solid rgba(255, 255, 255, 0.2);

    backdrop-filter: blur(10px);

}



.btn-secondary:hover {

    background: rgba(255, 255, 255, 0.2);

    transform: translateY(-2px);

    color: var(--white);

    text-decoration: none;

}



/* ===== CALCULATOR SECTION ===== */

.calculator-section {

    padding: var(--space-24) var(--space-4);

    background: var(--gray-50);

}



.container {

    max-width: 1200px;

    margin: 0 auto;

}



.section-header {

    text-align: center;

    margin-bottom: var(--space-16);

}



.section-title {

    font-size: clamp(2rem, 4vw, 3rem);

    font-weight: 700;

    color: var(--gray-900);

    margin-bottom: var(--space-4);

}



.section-subtitle {

    font-size: var(--space-5);

    color: var(--gray-600);

    max-width: 600px;

    margin: 0 auto;

}



.calculator-wrapper {

    background: var(--white);

    border-radius: var(--radius-2xl);

    box-shadow: var(--shadow-xl);

    padding: var(--space-12);

    margin: 0 auto;

    max-width: 800px;

    position: relative;

    overflow: hidden;

}



.calculator-wrapper::before {

    content: '';

    position: absolute;

    top: 0;

    left: 0;

    right: 0;

    height: 4px;

    background: linear-gradient(90deg, var(--primary), var(--secondary));

}



/* ===== HOW TO USE SECTION ===== */

.how-to-use-section {

    padding: var(--space-16) 0;

    background: linear-gradient(135deg, var(--gray-50) 0%, var(--white) 100%);

}



.how-to-content {

    max-width: 1200px;

    margin: 0 auto;

}



.step-card {

    display: flex;

    gap: 1.5rem;

    margin-bottom: 2.5rem;

    padding: 2rem;

    background: var(--white);

    border-radius: var(--radius-lg);

    box-shadow: var(--shadow);

    border-left: 4px solid var(--primary);

    transition: transform 0.2s ease, box-shadow 0.2s ease;

}



.step-card:hover {

    transform: translateY(-2px);

    box-shadow: var(--shadow-lg);

}



.step-number {

    display: flex;

    align-items: center;

    justify-content: center;

    width: 48px;

    height: 48px;

    background: var(--primary);

    color: var(--white);

    border-radius: 50%;

    font-weight: bold;

    font-size: 1.2rem;

    flex-shrink: 0;

}



.step-content h3 {

    color: var(--gray-800);

    margin-bottom: 1rem;

    font-size: 1.3rem;

    font-weight: 600;

}



.step-content h4 {

    color: var(--gray-700);

    margin: 1.5rem 0 0.75rem;

    font-size: 1.1rem;

    font-weight: 600;

}



.step-content ul {

    margin: var(--space-3) 0;

    padding-left: var(--space-6);

}



.step-content li {

    margin-bottom: var(--space-2);

    color: var(--gray-600);

    line-height: 1.6;

}



.tip-box,
.example-box {

    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);

    border: 1px solid #bae6fd;

    border-radius: var(--radius);

    padding: var(--space-4);

    margin: var(--space-4) 0;

}



.tip-box strong,
.example-box strong {

    color: var(--primary-dark);

}



.feature-grid {

    display: grid;

    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));

    gap: 1.5rem;

    margin: 2rem 0;

}



.feature-item {

    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);

    padding: 1.5rem;

    border-radius: 0.75rem;

    border-left: 4px solid #3b82f6;

    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);

    transition: all 0.3s ease;

    position: relative;

    overflow: hidden;

}



.feature-item::before {

    content: '';

    position: absolute;

    top: 0;

    left: 0;

    right: 0;

    height: 2px;

    background: linear-gradient(90deg, #3b82f6, #8b5cf6);

    transform: scaleX(0);

    transition: transform 0.3s ease;

}



.feature-item:hover {

    transform: translateY(-2px);

    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);

    border-left-color: #8b5cf6;

}



.feature-item:hover::before {

    transform: scaleX(1);

}



.feature-item h4 {

    color: #1e293b;

    margin-bottom: 0.75rem;

    font-size: 1.1rem;

    font-weight: 600;

    display: flex;

    align-items: center;

    gap: 0.5rem;

}



.feature-item p {

    color: #64748b;

    line-height: 1.6;

    margin: 0;

    font-size: 0.95rem;

}



.result-explanation,
.calculation-example {

    background: var(--gray-50);

    padding: var(--space-4);

    border-radius: var(--radius);

    margin: var(--space-4) 0;

}



.result-types ul {

    margin: var(--space-3) 0;

}



.use-cases-section,
.troubleshooting-section {

    margin-top: var(--space-12);

}



.use-cases-section h3,
.troubleshooting-section h3 {

    text-align: center;

    margin-bottom: var(--space-8);

    color: var(--gray-800);

    font-size: 1.5rem;

}



.use-cases-grid,
.troubleshooting-grid {

    display: grid;

    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));

    gap: var(--space-6);

}



.use-case,
.trouble-item {

    background: var(--white);

    padding: var(--space-6);

    border-radius: var(--radius-lg);

    box-shadow: var(--shadow);

    border-top: 3px solid var(--success);

}



.trouble-item {

    border-top-color: var(--warning);

}



.use-case h4,
.trouble-item h4 {

    color: var(--gray-800);

    margin-bottom: var(--space-3);

    font-size: 1.1rem;

}



.use-case p,
.trouble-item p {

    color: var(--gray-600);

    line-height: 1.6;

}



/* ===== FEATURES SECTION ===== */

.features-section {

    padding: var(--space-24) var(--space-4);

    background: var(--white);

}



.features-grid {

    display: grid;

    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));

    gap: var(--space-8);

    margin-top: var(--space-16);

}



.feature-card {

    background: var(--white);

    border-radius: var(--radius-xl);

    padding: var(--space-8);

    box-shadow: var(--shadow);

    border: 1px solid var(--gray-200);

    transition: all 0.3s ease;

    text-align: center;

}



.feature-card:hover {

    transform: translateY(-4px);

    box-shadow: var(--shadow-lg);

}



.feature-icon {

    width: 80px;

    height: 80px;

    margin: 0 auto var(--space-6);

    background: linear-gradient(135deg, var(--primary), var(--secondary));

    border-radius: var(--radius-full);

    display: flex;

    align-items: center;

    justify-content: center;

    font-size: 2rem;

    line-height: 1;

    font-family: "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji", sans-serif;

    color: var(--white);

}



.feature-title {

    font-size: var(--space-5);

    font-weight: 600;

    color: var(--gray-900);

    margin-bottom: var(--space-4);

}



.feature-description {

    color: var(--gray-600);

    line-height: 1.6;

}



/* ===== CALCULATOR TYPES SECTION ===== */

.calculator-types-section {

    padding: var(--space-24) var(--space-4);

    background: var(--gray-50);

}



.calculator-grid {

    display: grid;

    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));

    gap: var(--space-8);

    margin-top: var(--space-16);

}



.calculator-card {

    background: var(--white);

    border-radius: var(--radius-xl);

    padding: var(--space-8);

    box-shadow: var(--shadow);

    border: 1px solid var(--gray-200);

    transition: all 0.3s ease;

    text-decoration: none;

    color: inherit;

    display: block;

}



.calculator-card:hover {

    transform: translateY(-4px);

    box-shadow: var(--shadow-lg);

    text-decoration: none;

    color: inherit;

}



.calculator-icon {

    width: 60px;

    height: 60px;

    background: linear-gradient(135deg, var(--accent), var(--primary));

    border-radius: var(--radius-lg);

    display: flex;

    align-items: center;

    justify-content: center;

    font-size: 1.5rem;

    color: var(--white);

    margin-bottom: var(--space-4);

    line-height: 1;

    font-family: "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji", sans-serif;

}



.calculator-title {

    font-size: var(--space-5);

    font-weight: 600;

    color: var(--gray-900);

    margin-bottom: var(--space-3);

}



.calculator-description {

    color: var(--gray-600);

    line-height: 1.6;

    margin-bottom: var(--space-4);

}



.calculator-cta {

    color: var(--primary);

    font-weight: 600;

    display: inline-flex;

    align-items: center;

    gap: var(--space-2);

}



/* ===== FAQ SECTION ===== */

.faq-section {

    padding: var(--space-24) var(--space-4);

    background: var(--white);

}



.faq-container {

    max-width: 800px;

    margin: 0 auto;

}



.faq-list {

    display: flex;

    flex-direction: column;

    gap: var(--space-4);

    margin-top: var(--space-16);

}



.faq-item {

    background: var(--white);

    border: 1px solid var(--gray-200);

    border-radius: var(--radius-lg);

    overflow: hidden;

    transition: all 0.3s ease;

}



.faq-item.active {

    box-shadow: var(--shadow-md);

}



.faq-question {

    padding: var(--space-6);

    background: var(--gray-50);

    cursor: pointer;

    font-weight: 600;

    color: var(--gray-900);

    display: flex;

    justify-content: space-between;

    align-items: center;

    transition: all 0.3s ease;

    border: none;

    width: 100%;

    text-align: left;

}



.faq-question:hover {

    background: var(--gray-100);

}



.faq-question::after {

    content: '+';

    font-size: 1.5rem;

    font-weight: 400;

    transition: transform 0.3s ease;

}



.faq-item.active .faq-question::after {

    transform: rotate(45deg);

}



.faq-answer {

    max-height: 0;

    overflow: hidden;

    transition: max-height 0.3s ease;

    padding: 0 var(--space-6);

}



.faq-answer>div {

    padding: var(--space-6) 0;

    color: var(--gray-600);

    line-height: 1.6;

}



/* ===== ANIMATIONS ===== */

@keyframes fadeInUp {

    from {

        opacity: 0;

        transform: translateY(30px);

    }

    to {

        opacity: 1;

        transform: translateY(0);

    }

}



/* ===== RESPONSIVE DESIGN ===== */

@media (max-width: 768px) {

    .hero {

        padding: var(--space-12) var(--space-4);

        min-height: 80vh;

    }



    .hero-cta {

        flex-direction: column;

        align-items: center;

    }



    .calculator-wrapper {

        padding: var(--space-6);

        margin: 0 var(--space-2);

    }



    .features-grid,

    .calculator-grid {

        grid-template-columns: 1fr;

        gap: var(--space-6);

    }



    .calculator-card {

        padding: var(--space-6);

    }

}



@media (max-width: 480px) {

    .hero-title {

        font-size: 2rem;

    }



    .hero-subtitle {

        font-size: 1.125rem;

    }



    .hero-description {

        font-size: var(--space-4);

    }



    .calculator-wrapper {

        padding: var(--space-4);

    }

}



/* ===== PERFORMANCE OPTIMIZATIONS ===== */

.hero,

.calculator-wrapper,

.feature-card,

.calculator-card {

    will-change: transform;

    contain: layout style paint;

}



.hero-title,

.hero-subtitle,

.hero-description {

    will-change: opacity, transform;

}



.faq-item {

    will-change: transform;

}



.faq-answer {

    will-change: max-height;

}



/* ===== ACCESSIBILITY ===== */

@media (prefers-reduced-motion: reduce) {

    * {

        animation-duration: 0.01ms !important;

        animation-iteration-count: 1 !important;

        transition-duration: 0.01ms !important;

    }

}



.btn:focus,

.faq-question:focus {

    outline: 2px solid var(--primary);

    outline-offset: 2px;

}


/* ===== DARK MODE SUPPORT ===== */

@media (prefers-color-scheme: dark) {

    :root {

        --white: #111827;

        --gray-50: #1f2937;

        --gray-100: #374151;

        --gray-200: #4b5563;

        --gray-300: #6b7280;

        --gray-400: #9ca3af;

        --gray-500: #d1d5db;

        --gray-600: #e5e7eb;

        --gray-700: #f3f4f6;

        --gray-800: #f9fafb;

        --gray-900: #ffffff;

    }

}



/* ===== ALL CALCULATORS SECTION STYLES ===== */

.calculator-category {

    margin-bottom: 4rem;

    padding: 2rem;

    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);

    border-radius: 1rem;

    border: 1px solid #e2e8f0;

    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);

    position: relative;

    z-index: 1;

}



.calculator-category:last-child {

    margin-bottom: 0;

}



.category-title {

    font-size: 1.5rem;

    font-weight: 700;

    color: #1e293b;

    text-align: center;

    margin-bottom: 2rem;

    padding-bottom: 1rem;

    border-bottom: 2px solid #3b82f6;

    position: relative;

}



.category-title::after {

    content: '';

    position: absolute;

    bottom: -2px;

    left: 50%;

    transform: translateX(-50%);

    width: 60px;

    height: 2px;

    background: linear-gradient(90deg, #3b82f6, #8b5cf6);

}



.calculator-category .calculator-grid {

    display: grid;

    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));

    gap: 1.5rem;

    margin-top: 1.5rem;

}



.calculator-category .calculator-card {

    background: white;

    border-radius: 0.75rem;

    padding: 1.5rem;

    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);

    border: 1px solid #e2e8f0;

    transition: all 0.3s ease;

    text-decoration: none;

    color: inherit;

    display: block;

    position: relative;

    overflow: hidden;

}



.calculator-category .calculator-card::before {

    content: '';

    position: absolute;

    top: 0;

    left: 0;

    right: 0;

    height: 3px;

    background: linear-gradient(90deg, #3b82f6, #8b5cf6);

    transform: scaleX(0);

    transition: transform 0.3s ease;

}



.calculator-category .calculator-card:hover {

    transform: translateY(-4px);

    box-shadow: 0 10px 25px -3px rgba(0, 0, 0, 0.1);

    border-color: #3b82f6;

}



.calculator-category .calculator-card:hover::before {

    transform: scaleX(1);

}



.calculator-category .calculator-icon {

    font-size: 2.5rem;

    margin-bottom: 1rem;

    display: block;

    text-align: center;

    line-height: 1;

    font-family: "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji", sans-serif;

}



.calculator-category .calculator-title {

    font-size: 1.25rem;

    font-weight: 600;

    color: #1e293b;

    margin-bottom: 0.75rem;

    text-align: center;

}



.calculator-category .calculator-description {

    font-size: 0.9rem;

    color: #64748b;

    line-height: 1.5;

    margin-bottom: 1rem;

    text-align: center;

}



.calculator-category .calculator-cta {

    display: inline-block;

    background: linear-gradient(135deg, #3b82f6, #8b5cf6);

    color: white;

    padding: 0.75rem 1.5rem;

    border-radius: 0.5rem;

    font-weight: 600;

    font-size: 0.9rem;

    text-decoration: none;

    transition: all 0.3s ease;

    text-align: center;

    width: 100%;

    box-sizing: border-box;

}



.calculator-category .calculator-cta:hover {

    background: linear-gradient(135deg, #2563eb, #7c3aed);

    transform: translateY(-2px);

    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);

}



/* Mobile Responsiveness for Calculator Categories */

@media (max-width: 768px) {

    .calculator-category {

        padding: 1.5rem;

        margin-bottom: 2rem;

    }



    .category-title {

        font-size: 1.25rem;

        margin-bottom: 1.5rem;

    }



    .calculator-category .calculator-grid {

        grid-template-columns: 1fr;

        gap: 1rem;

    }



    .calculator-category .calculator-card {

        padding: 1.25rem;

    }



    .calculator-category .calculator-icon {

        font-size: 2rem;

    }



    .calculator-category .calculator-title {

        font-size: 1.1rem;

    }

}


/* ============================================================
   MOBILE (max 768px) — Phones
   ============================================================ */
@media (max-width: 768px) {

    /* Container */
    .container {
        padding: 0 1.25rem;
    }

    /* Section Spacing */
    .hero,
    .calculator-section,
    .how-to-use-section,
    .features-section,
    .calculator-types-section,
    .faq-section {
        padding: 3rem 0 !important;
    }

    /* Hero */
    .hero {
        padding: 2.5rem 0 !important;
        text-align: center;
    }

    .hero-title {
        font-size: clamp(1.75rem, 8vw, 2.5rem) !important;
        margin-bottom: 1rem;
    }

    .hero-subtitle {
        font-size: 1.1rem !important;
        margin-bottom: 1.5rem;
        padding: 0 0.5rem;
    }

    .hero-description {
        font-size: 0.95rem;
        margin-bottom: 2rem;
        line-height: 1.5;
    }

    .hero-cta {
        display: flex;
        flex-direction: column;
        gap: 0.75rem;
        padding: 0 1rem;
    }

    .hero-cta .btn {
        width: 100%;
        justify-content: center;
        padding: 1rem !important;
        font-size: 1.05rem;
    }

    /* Typography */
    .section-title {
        font-size: 1.75rem !important;
        padding: 0 1rem;
    }

    .section-subtitle {
        font-size: 1rem !important;
        padding: 0 1.5rem;
    }

    /* Calculator Wrapper */
    .calculator-wrapper {
        padding: 1.5rem 1rem !important;
        margin: 0 0.5rem !important;
        border-radius: 1rem !important;
        box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1) !important;
    }

    /* Features / Calculator grids */
    .trust-signals,
    .features-grid,
    .calculator-grid {
        grid-template-columns: 1fr !important;
        gap: 1.5rem !important;
    }

    /* Feature cards */
    .feature-card {
        padding: 1.5rem 1rem !important;
    }

    .feature-title {
        font-size: 1.1rem !important;
    }

    .feature-description {
        font-size: 0.9rem !important;
    }

    /* Icons */
    .feature-icon,
    .calculator-icon {
        width: 50px !important;
        height: 50px !important;
        font-size: 1.25rem !important;
    }

    /* Step Cards (How-To section) */
    .step-card {
        flex-direction: column !important;
        gap: 0.75rem !important;
        padding: 1.25rem !important;
        margin-bottom: 1.25rem !important;
    }

    .step-number {
        width: 40px !important;
        height: 40px !important;
        font-size: 1rem !important;
        flex-shrink: 0;
    }

    .step-content h3 {
        font-size: 1.1rem !important;
    }

    .step-content h4 {
        font-size: 1rem !important;
        margin-top: 0.75rem;
    }

    .step-content p,
    .step-content li {
        font-size: 0.92rem !important;
        line-height: 1.6;
    }

    /* Inner Feature Grid (inside How-To) */
    .feature-grid {
        grid-template-columns: 1fr !important;
        gap: 0.75rem !important;
    }

    .feature-item {
        padding: 1rem !important;
    }

    .feature-item h4 {
        font-size: 0.95rem !important;
    }

    /* Tip & Example Boxes */
    .tip-box,
    .example-box {
        font-size: 0.9rem !important;
        padding: 0.75rem 1rem !important;
        border-radius: 0.5rem;
    }

    /* Result & Calculation Example */
    .result-explanation,
    .calculation-example,
    .result-types {
        padding: 0.75rem 1rem !important;
        font-size: 0.9rem !important;
    }

    /* Use Cases & Troubleshooting */
    .use-cases-grid,
    .troubleshooting-grid {
        grid-template-columns: 1fr !important;
        gap: 0.75rem !important;
    }

    .use-case,
    .trouble-item {
        padding: 1rem 1.25rem !important;
    }

    .use-case h4,
    .trouble-item h4 {
        font-size: 1rem !important;
    }

    /* How-To Header */
    .how-to-use-section .section-header {
        margin-bottom: 2rem !important;
    }

    /* FAQ */
    .faq-question {
        padding: 1.25rem 1rem !important;
        font-size: 1rem;
    }

    .faq-answer>div {
        padding: 1rem !important;
        font-size: 0.95rem;
    }

    /* Category Cards */
    .calculator-category {
        padding: 1.5rem 1rem !important;
        margin-left: 0.5rem !important;
        margin-right: 0.5rem !important;
    }

    .calculator-category .calculator-grid {
        display: grid !important;
        grid-template-columns: 1fr !important;
    }
}


/* ============================================================
   EXTRA SMALL (max 400px) — Small Android Phones
   ============================================================ */
@media (max-width: 400px) {
    .hero-title {
        font-size: 1.4rem !important;
        line-height: 1.3 !important;
    }

    .btn {
        padding: 0.875rem 0.5rem !important;
        font-size: 0.95rem !important;
    }

    .step-number {
        width: 36px !important;
        height: 36px !important;
        font-size: 0.95rem !important;
    }

    .section-title {
        font-size: 1.4rem !important;
    }
}


/* ============================================================
   TABLET (769px – 1024px) — iPad & Medium Screens
   ============================================================ */
@media (min-width: 769px) and (max-width: 1024px) {
    .hero {
        padding: 3.5rem 2rem !important;
    }

    .hero-title {
        font-size: clamp(2rem, 4vw, 3rem) !important;
    }

    .hero-cta {
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.75rem;
    }

    .hero-cta .btn {
        flex: 1 1 200px;
        text-align: center;
        justify-content: center;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr) !important;
    }

    .calculator-grid {
        grid-template-columns: repeat(2, 1fr) !important;
    }

    .step-card {
        gap: 1.25rem;
        padding: 1.5rem;
    }

    .feature-grid {
        grid-template-columns: repeat(2, 1fr) !important;
    }

    .use-cases-grid,
    .troubleshooting-grid {
        grid-template-columns: repeat(2, 1fr) !important;
    }

    .calculator-wrapper {
        padding: 2rem !important;
    }

    .section-title {
        font-size: 2rem !important;
    }
}


/* ============================================================
   GLOBAL SAFETY — Prevent horizontal scroll on all devices
   ============================================================ */
html,
body {
    overflow-x: hidden;
    max-width: 100%;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}